When I was in middle school and high school, we had a grueling schedule. At the time I thought it was normal - even reasonable - to be expected to deal with the workloads and timetables laid on us. However, as soon as I graduated high school I quickly realized how insane of an expectation that truly had been. I think it's necessary that schools like mine change their approach so current and incoming students don't go through the same experience.
First, let's focus on the schedule. There were seven to nine periods each day, but let's assume seven classes and a lunch to keep things simple. That meant eight context switches, up to seven homework assignments, and often seven books to carry. We were given three to five minutes between classes to get between classes. It was on us to get to our next class on time, regardless of how long the teacher in the previous class had held us, or whether it's physically possible to move that fast.
Each of these context switches is quite expensive, both in terms of time and focus. Preparing for each class as you enter and cleaning up to leave easily wastes two minutes per class in addition to the time to move between classes, totaling to about 30 minutes of wasted time (most of the length of a normal class period). Additionally, moving between classes means losing any focus you had for the previous class just to start to focus on the next.
Needing to attend every class every day also leads to very random homework workloads. In the worst cases, all classes will assign homework due to the next day, possibly requiring all free time that night to complete. Teachers can, in some cases, work together to mitigate this issue, but doing so requires constant effort from all involved teachers, and may not be effective for all students.
Making matters worse, students were required to bring their loaned books to class every day. Optimistically this isn't a big deal - they can just leave the books in their locker and get each one as needed - but the short breaks between classes rarely provide enough time to visit a locker regularly. The worst schedule I had left me with a single locker access after third period, leaving me with my five largest books to lug around for the rest of the day all semester. Depending on homework load, this also requires that the student bring most of their books back and forth from home each day, and making a mistake by leaving the wrong book will often prevent the completion of a homework assignment.
I propose that both middle and high school should change to scheduling more similar to college. Each day should have fewer, longer periods - perhaps three long classes and some shorter ones to match lunch periods. Students' classes would only run two or three days a week. Careful distribution of period assignments for classes and students would allow the same total amount of class time, but with longer breaks or a shorter day. Guaranteed days off of each class would alleviate periods of unmanageable homework loads, and reduce the number of books carried to and from school as well as between classes, while longer periods provide a longer time where students are able to fully focus on the material being taught. I suspect having to prepare for fewer classes each day would also be easier on teachers. Overall, I feel as though this change would be simple to enact, but would have a profound impact on the quality of life for the students.